Adam charles girard and ernest auguste georges street



(No Model.)

A. 0. GIRARD & E. A. G. STREET. ELEGTRIG FURNACE.

No. 556.626. Patented Mar. 17-, 1896.

KHDREW EGRIKAM. PNDTDUT'HQWASHINGTON. D C

UNITED STATES PATENT OFFICE.

ADAM CHARLES GIRARD AND ERNEST AUGUSTE GEORGES STREET, OF PARIS, FRANCE.

ELECT-RIC FURNACE.

SPECIFICATION forming part of Letters Patent No. 556,626, dated March 17, 1896.

Application filed May 24,1895. Serial No. 550,538. (No model.) Patented in France May 25,1893,N0. 230,341; in England July 8, 1893,1T0. 13.340; in Germany August 2,1893, No. 81,479 in Austria-Hungary August 2, 1893,1To. 41,930 and No. 65,879; in Belgium September 9, 1893, No. 106,309; in Switzerland September 14, 1893, Nos. 7,460 and 7,562; in Italy September 30, 1893, N0. 267, and in Spain October 27,1893, No. 14,950.

. To all whom it may concern.-

Be it known that we, ADAM CHARLES GI- RARD, chemist,residing at 7 Rue du Bellay, and ERNEST AUGUSTE GEORGES STREET, engineer, residing at 39 Rue J oubert, Paris, France, citi- Zens of the Republic of France, have invented certain new and useful Improvements in and Relating to Electric Furnaces, (for which we have obtained patents in France, No. 230, 341 dated May 25, 1893, and certificate of addition thereto dated June 8, 1893; in Great Britain, No. 13,340, dated July 8, 1893; in Germany, certificate of addition No. 81,479, dated August 2, 1893; in Austria-Hungary, No. 41,930 and No. 65,879, dated August 2, 1893; in Switzerland,Nos. 7,460 and 7, 562, dated September 14, 1393; in Belgium, No. 106,309, dated September 9,1893; in Spain, No. 14,950, dated October 27, 1893, and inltaly, No. 267, dated September 30, 1893,) of which the following is a specification, reference being had to the accompanying drawings.

This invention relates to electric furnaces, and has for its object to provide new an zl improved means for heating materials that are conductors of electricity, and which are in the form of bars or rods of any desired cross section, and which bars or rods may in some cases be made hollow for containing the materials to be heated. This object is accomplished in the manner and by the means hereinafter described and claimed, reference being made to the accompanying drawings, in Which Figure 1 is a sectional elevation of sufficient of an electric furnace to illustrate our inven tion. Fig. 2 is an end elevation of the same.

- Fig. 3 is a sectional elevation showing a modification of our invention. Fig. 4 is a detail sectional view of a portion of one of the electrodes. Fig. 5 is a detail sectional view show ing the preferred manner of constructing the heating-chamber proper and the parts immediately surrounding the heating chamber, and Fig. 6 is a detail sectional view of a hollow cylinder designed to contain a fusible or non-fusible substance or material which is not in the form of a bar or rod.

In order to enable those skilled in the art to make and use our invention, we will now describe the same in detail, referring to the drawings, wherein the letter 7) indicates the external casing of a furnace structure. This furnace structure may be of any desired construction suitable for the purpose in hand, and centrally it is provided with a cavity eonstituting a heating-chamber As here shown, the external casing l) is designed to be of metal, and the heating-chamber c is formed in a block aof any material suitable for the purpose in hand. \Ve prefer, however, to construct the heating-chamber c in a carbon block (1 as shown in Fig. 5, and to surround this carbon block with ordinary carbon bricks a and magnesia bricks (0*, outside of which latter are ordinary firebrieks o As shown in Fig. 1, the furnace structure is provided with a radial channel (1, extending from the heatingehamber c to the exterior of the furnace and designed to receive a carbon rod (1.

Extending longitudinally through the block a and heating-chamber c, and at about right angles to the aforesaid channel (1, is another channel a, through which the bar or rod 6 to be treated is introduced. *0 impart to this bar or rod a continuous longitudinal movement by feed-rollersfor other means,whereby the whole of said bar or rod is caused to traverse the heating-chamber c. The speed at which the bar or rod is fed through the fur nace is regulated according to the sectional area and mass of the bar or rod under treatment and according to the temperature to which it is to be heated.

The carbon rod (Z and the bare to be heated constitute electrodes, between which a voltaic are can be produced within the heating-chamber c, the said are remaining stationary in the heating-chamber while the bar or rod 0 is fed through the furnace. The are thus impinges on the moving bar or rod in a continuous line, thereby heating it to a very high temperature.

2 i are binding-screws by which the wires t e, conveying the electric current from a suitable source of electricity, are connected to the furnace.

It will be readily understood that the speed of the moving bar or rod e controls the mean temperature which it will attain.

The current is conducted to the traveling rod or bar by means of a. suitable contact 'or brush, which is so arranged that while offering little impediment to the movement of the rod it insures a good electric contact therewith.

In the drawings we have shown hollow glands 0, provided with three spring-contacts 0, whose outer ends are secured to the gland by set-screws 0 These set-screws also enable the position of the spring-contacts to be readily adjusted.

The length of the are between the carbon 01 and the rod 6 may be kept constant by means of an arrangement such as is customarily employed for a similar purpose in arc lamps.

In some instances we dispense with the block a and line the casing of the furnace with some suitable refractory material that is a bad conductor of heat, such as retort-carbon or agglomerated carbon, said lining being insulated from the electrodes. In other instances we employ neither the block nor the lining.

The operation of the above-described apparatus is continuous, as the rods or the like to be treated may be caused to succeed each other without interruption.

\Vhen it is desired to heat the rod or the like in an atmosphere of appropriate gas with exclusion of the ordinary atmosphere, we provide stu ffing-boxes g and h, through which the bar or rod is passed on entering and leaving the furnace. We also provide a stuffingbox is, through which the carbon electrode at passes. Inlet and outlet orifices for the gas are provided at Z and m, the same having suitable stop-taps, and, if desired, a pressure-gage may be provided at n for indicating the pressure of gas in the furnace. The stuffing-boxes g and h are connected with the furnace by tubes or chambers 19 13, through which the gas or gases employed reach the furnace. The traveling bar or rod before entering and after leaving the furnace travels through these tubes or chambers and is thus prepared for the materials are placed.

treatment in the furnace, and after its treatment is also cooled before reaching the external atmosphere. If desired, the said tubes or chambers 19 and the carbon electrode (1 may be electrically insulated from the metallic parts of the furnace.

It will be understoodthat when the refractory block is dispensed with the furnace is in other respects practically the same as above described.

In some instances we so construct the furnace that the bar or rod 6 can be subjected to the action of more than one electric are.

When it is desired to treat materials that are not themselves in the form of bars or rods, the aforesaid bars or rods can be made as hollow cylinders, as at c, Fig. 6, within which The hollow cylinders e are each closed at one end, as at 6 and at the opposite end provided with a removable and replaceable plug or stopper 6 The hollow cylinders may be composed of any suitable substance that will withstand the temperature to which the materials are to be subjected. The hollow cylinder is designed to be fed through the furnace in substantially the same manner as the bar or rod 6, described with reference to Fig. 1.

The furnaces are provided with stufiingboxes and gas'inlet and outlet pipes.

In a modification of thefurnace we provide means for enabling an equal distribution of the electric are over the substance or material under treatment. For achieving this result we cause the arc to rotate around the substance or material under treatment by producing a suitable magnetic field in the furnace. When applied to the furnace above described for the treatment of bars, rods and the like, we substitute for the carbon electrode d carbons S S, arranged as shown at Fig. 3. These carbons may be of the section shown in Fig. i and are formed with a transverse hole S of suitable shape, through which the rod or bar 0 to be treated passes, and the arc is formed between said rod or bar and the interior surface of the hole. The arcs may be struck by first drawing the carbons S S outwardly until the inner surface of their holes touches thetransverse bar or rod 6, and then pushing them back to their normal position, or the arc may be struck in any other suitable manner. This are is an element of current.

Having now described our said invention and in What manner the same is to be performed, we claim 1. An electric furnace having a heatingchamber, and a passagc-waythrough it for furnace and acting upon the said object to feed it progressively through the heatingchamber, an electrode projecting into the heating-chamber, and suitable electric connections for producing a voltaic are between said electrode and said object, substantially as described.

2. An electric furnace having a heatingchamber,and a passage-way through it for receiving the object to be heated, combined with mechanism, substantially as described, arranged in operative connection with the furnace and acting upon the said object to feed it progressively through the heatingchamber, an electrode projecting into the heating-chamber, suitable electric connections for producing a voltaic are between said electrode and said object, and gas inlet and outlet pipes arranged in relation to the said object and provided with means for circulating a gaseous fiuid about the object under treatment while excluding atmospheric air, substantially as described.

3. The combination in an electric furnace,

of a heating-chamber, a longitudinal passageway extending through the chamber, atubular cylinder for containing the material to be heated, means for feeding the cylinder through said longitudinal passage-way, an electrode projecting into the heatingchamber, suitable terminals, and electric conductors connected with said terminals for enabling a voltaic arc to be produced between the electrode and the said cylinder, substantially as described.

4. The combination with an electric furnace having a heating-chamber and a passage-way through said chamber,- of lengthwise-movable electrodes projecting into said heating-chamher and constructed with transverse orifices through which the object to be heated passes, and suitable electric connections for producing a voltaic are between the electrodes and the said object, said electrodes being movable for the purpose of striking the arc, substantially as described.

5. An electric furnace consisting of a refractory block or blocks of some material that is a bad conductor of heat, a heating-chamber such as cformed in a carbon block located within said refractory block or blocks, a surrounding casing such as b, stufling-boxes such as g, h, is, tubular chambers such as 19 connecting the stuffing-boxes g, h with the outer casing 12, glands such as 0 containing springcontacts such as 0, feed-rollers such as f for progressively feeding the rod or bar to be treated through the furnace, cocks such as Z, m for enabling gaseous or other fluid to circulate around the rod or bar 6, a radiallyarranged carbon electrode adapted to enter the heating-chamber c, and terminals such as ifor enabling the electric conductors to be connected to the furnace, substantially as described and for the purposes specified.

In witness whereof we have hereunto set our hands this 10th day of May, 1895.

ADAM CHARLES GIRARD. ERNEST AUGUSTE GEORGES STREET. Vitnesses JEAN ALBERT LUDER, PAUL JEAN GIRARD. 

